Vehicle Dynamic Target Tracking System Based On 2-DOF PTZ Control

In recent years,due to the wide application and development of photoelectric tracking technology,photoelectric tracking systems are not only used in conventional shooting range experiments,but also extended to many fields such as military and civilian industries.With the emergence of new measurement and control platforms such as vehicles,ships,airplanes,and satellites,the requirements for photoelectric tracking systems have become higher and higher.Traditional ground-based fixed base photoelectric tracking systems can no longer meet the needs,and photoelectric tracking equipment has begun to Mobile platform.According to the different carriers,the photoelectric tracking system can be divided into ground-based,vehicle-mounted,ship-borne,air-borne,space-borne,and missile-borne.Compared with the photoelectric tracking system on a ground-based fixed base,higher requirements are placed on optoelectronic equipment under mobile conditions.The photoelectric equipment installed on the mobile platform changes its pose or is disturbed by the complex environment during the movement.The tracking equipment will be affected by these carrier coupling interference,which not only affects the imaging quality and causes the image to be blurred,but also affects the accuracy of the tracker to extract the target miss amount,resulting in a decrease in tracking performance.Therefore,in order to track the target stably when the carrier and the target are in motion,the photoelectric tracking system must adopt corresponding techniques to isolate the disturbance of the carrier,and the servo tracking system must have strong dynamic anti-disturbance ability to ensure the direction of the visual axis.stable.It can be seen that the Line-Of-Sight of the photoelectric tracking system is the key to the photoelectric LOS-Stabilized tracking technology,and it is of great significance to study it.The research in this thesis is dedicated to the Line-Of-Sight Stabilization of the mobile photoelectric tracking system.In this thesis,based on the Line-Of-Sight Stabilization technology,a set of vehicle dynamic target tracking system based on dual-degree-of-freedom pan/tilt control is independently designed and built,and the Line-Of-Sight Stabilization is proposed to simultaneously balance the influence of position and attitude changes on the Line-Of-Sight during the movement of the carrier,and apply it to the system platform to verify the effect of the Line-Of-Sight.First of all,this thesis introduces the mechanical structure of the system platform,hardware selection,software architecture and the mechanical movement of the carrier.Then the research plan of the system is given.The servo control problem of the maneuvering photoelectric tracking system with the aiming target is described as a dual-task problem of Line-Of-Sight Stabilization and Line-Of-Sight track using coordinate transformation,and the calculation of Los-Stabilized tracking angle is given.At the same time,the Los-Stabilized disturbance estimation algorithm is proposed to estimate the Los-Stabilized disturbance caused by vehicle motion,and the effectiveness and accuracy of the algorithm are verified by simulation.At the same time,it briefly introduces the target detection algorithm used in this thesis.Then the miss coupling between the azimuth and the pitch of the dual-degree-of-freedom gimbal system is compensated and decoupled,so that the azimuth subsystem and the pitch subsystem can be designed independently.Then take the azimuth subsystem as an example to carry out system modeling and corresponding controller design.A dual-loop control structure of image loop and angle loop is adopted to improve the visual axis pointing performance during vehicle movement.The angle loop uses a PD controller to improve the response speed of the system without overshoot,and the image loop uses a PI controller to improve the steady-state accuracy of the system.On this basis,this thesis uses the estimated value of the boresight disturbance to perform equivalent compound control,designs the corresponding feedforward controller according to Nehari’s theorem,and verifies its control effect through simulation.Finally,the Line-Of-Sight stabilization proposed in this thesis is implemented on an experimental platform built,and the results of the sports car are analyzed.At the same time,the target Los-Stabilized aiming errors under different control structures and different vehicle speeds are compared.The results show that the Line-Of-Sight proposed in this thesis has a good Line-Of-Sight stabilization effect on the system,and effectively isolates the influence of vehicle movement on the Los-Stabilized tracking.